US8254408B2 - Modular implementation of a protocol in a network device - Google Patents

Abstract

A system includes a gateway node that contains modular cards that separately implement control and data planes of a network protocol. The separate data and control cards provide for improved system reliability and improved flexibility in managing bandwidth. Control or data cards can be added to the gateway node as needed based on system load.

Description

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No. 10/374,712, filed Feb. 27, 2003, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

A. Field of the Invention

The present invention relates generally to communication networks, and more particularly, to implementing routing protocols in a wireless network.

B. Description of Related Art

Global System for Mobile Communications (GSM) is a leading digital wireless communications standard. A basic GSM network is designed for voice traffic. GPRS (General Packet Radio Service) is an enhancement to GSM that allows GSM operators to provide packet data services to their wireless subscribers.

Before GPRS, the radio capacity in a wireless network was conventionally used for calls and data transmission within the GSM network in a rather inefficient manner. For data transmission, the entire channel was occupied and was often insufficiently used. Through GPRS, more than one user may share the same channel, allowing for a more efficient allocation of channel resources. Additionally, a GPRS mobile phone may use several channels for data transfer, thus facilitating greater transfer speeds. Through GPRS, a mobile phone user could simultaneously make a call and receive an email message.

A GPRS network uses a number of protocols, one of which is the GPRS tunnel protocol (GTP). GTP is a protocol designed to tunnel user data and signaling information between nodes in a GPRS network. The GTP protocol includes a call-setup (signaling/control plane) component and a bearer traffic (data plane) component. Conventionally, the control plane component and the data plane component of the GTP protocol are handled by nodes in the GPRS network using a single integrated unit to handle processing for both the call setup and bearer traffic components of the protocol. This technique may lack flexibility and scalability.

Thus, it would be desirable to handle traffic in a GPRS network in a manner that is both flexible and modular from the standpoint of the GPRS network nodes.

SUMMARY OF THE INVENTION

Systems and methods consistent with principles of the invention include a router that supports removable cards, including separate cards for handling call setup/control functions and packet forwarding functions under protocols such as GTP.

One aspect of the invention is directed to a device for implementing a network protocol. The device includes a first type of interface card and a second type of interface card. The first type of interface card is configured to perform functions related to establishing communication sessions under the network protocol. The second type of interface card performs functions related to data transfer in a communication session established by the first type of interface card.

Another aspect of the invention is directed to a method. The method includes receiving a request that a call be completed in a network, the request being processed by a master control card in a gateway node. The method further includes transferring the request to a slave control card in the gateway node and initiating, by the slave control card, a communication session with a destination device. The method still further includes transferring the communication session to a data card in the gateway node when the communication session is initiated and forwarding data of the communication session via the data card.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the invention and, together with the description, explain the invention. In the drawings,

FIG. 1 is a diagram illustrating an exemplary network consistent with principles of the invention;

FIG. 2 is a diagram illustrating the GGSN shown inFIG. 1 in additional detail;

FIG. 3 is a flow chart illustrating call setup and data transfer consistent with principles of the invention; and

FIG. 4 is a diagram illustrating a portion of the network ofFIG. 1 relating to the call setup and data transfer illustrated inFIG. 3.

DETAILED DESCRIPTION

The following detailed description of the invention refers to the accompanying drawings. The same reference numbers may be used in different drawings to identify the same or similar elements. Also, the following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims and equivalents.

A router at a gateway GPRS support node (GGSN) includes a number of removable cards. The cards may include, in addition to media cards that physically connect to an external network, separate cards for handling call setup/control functions and packet forwarding functions under GTP. The cards are interchangeable and can be added and removed as needed.

Exemplary Network

FIG. 1 is a diagram illustrating anexemplary network100 consistent with principles of the invention. Network100 includes end-users101A and101B that communicate wirelessly withbase stations102A and102B (collectively referred to as end-users101 and base stations102, respectively). End-users101 may include any device that communicates wirelessly, such as, for example, wireless phones, personal digital assistants, or notebook computers. With any of these devices, users may communicate using wireless voice and/or data services.

Information received at base stations102 may be forwarded through a number of network elements, including base transceiver stations (BTSs)103 and base station controller (BSC)104. BTSs103 may be transceivers that receive and broadcast information via base stations102. BSC104 may be a packet-based device that connects BTSs103 to a mobile switching center (MSC)105, which may further connect to a network such as a public switched telephone network (PSTN)110. In this manner, through MSC105, end-users101 can communicate with users on thePSTN110.

BSC104 may additionally connect to a serving GPRS support (SGSN)node106 via anIP network111. SGSN106 can be thought of as a packet-switched mobile switching center. SGSN106 delivers packets to end-users101 within its service area. SGSN106 may obtain profile data of GPRS end-users, detect new end-users in a given service area, process registration of new end-users, and keep a record of the location of an end-user user with a service area. Thus, in general, SGSN106 performs mobility management functions for the mobile end-users within its service area.

GGSN107 acts as an interface from SGSNs to external IP networks such as thepublic Internet113, other mobile service provider's GPRS services, or private enterprise orcorporate networks114. GGSN107 may maintain routing information that is necessary to tunnel protocol data units to SGSN106, under, for example, GTP.

Additional details of the implementation of BTSs103,BSC104, MSC105, and SGSN106 will not be described further herein, as these elements are generally well known in the art.

GGSN107

FIG. 2 is a diagram illustrating GGSN107 in additional detail consistent with principles of the invention.GGSN107 may be generally structured in a manner similar to a router.GGSN107 may include one or more packet forwarding engines (PFEs)204A,204B . . .204C (collectively referred to as PFEs204) and arouting engine202. In general,GGSN107 receives one or more data streams from a physical link, processes the data streams to determine destination information, and transmits the data streams out on links in accordance with the destination information.

Routing engine202 performs high-level management functions forGGSN107. For example,routing engine202 communicates with external networks and systems, such asnetworks113 and114, connected toGGSN107 to exchange information regarding network topology.Routing engine202 may create routing tables based on network topology information and create forwarding tables based on the routing tables and forwards the forwarding tables to PFEs204. PFEs204 may use the forwarding tables to perform route lookup for incoming packets (or other structured data units).Routing engine202 also performs other general control and monitoring functions forGGSN107.

One of PFEs204,PFE204B, is shown inFIG. 2 in detail. As shown,PFE204B may contain flexible port concentrators (FPCs)205A,205B . . .205C that have slots that hold one or more physical interface cards (PICs)206A-206F in physical slots. PICs206 may be modular and replaceable elements within FPCs205. In one implementation, PICs206 may also be hot-swappable, meaning that they may be inserted and removed whileGGSN107 is operating. Any one ofPICs206A-206F may be inserted in a slot of any ofFPCs205A-205C.

PICs206 may perform a number of different functions.PICs206E and206F, for example, may be transport media cards that physically receive and transmit data on a network (connection not shown), such asnetwork112,113, or114 (FIG. 1). EachPIC206E and206F may be designed to communicate with one of many types of transport media, such as optical fiber or Ethernet cable. The transmitted and received data may be formatted according to one of several protocols, such as the synchronous optical network (SONET) standard, an asynchronous transfer mode (ATM) technology, or Ethernet.Different PICs206E and206F are designed to handle different types of transport media. For example,PIC206E may be an interface for an optical link whilePIC206F may be an interface for an Ethernet link.

PICs206A-206D may not be media cards. Instead, consistent with principles of the invention, these PICs may be interface cards designed to handle the processing for a transmission protocol, such as GTP. In this manner,PICs206A-206D may augment the traditional routing functions ofrouting engine202 andPFEs204A-204C by allowing these elements to function as a GGSN.

PICs206A-206D may include separate PICs for handling control functions and data delivery in GTP. These PICs are illustrated inFIG. 2 asGGSN control PICs206A and206B andGGSN data PICs206C and206D. In general,control PICs206A and206B handle call setup.Data PICs206C and206D handle packet forwarding once a call session has been setup by one ofcontrol PICs206A and206B.

FIG. 3 is a flow chart illustrating call setup and data transfer inGGSN107 consistent with principles of the invention. In the example shown inFIG. 3, an end-user101 initiates a call from a mobile phone requesting data, such as a corporate (enterprise) network, such as one ofcorporate networks114. A salesman away from the office may, for example, remotely check a company email account via a cell phone. The call is initially transferred throughBTS103,BSC104, andIP network111 toSGSN106.

SGSN106, upon receiving the call, requests a GTP connection with GGSN107 (Acts301 and302). AtGGSN107, the request is received at one ofmedia PICs206E and206F, and transferred to one ofcontrol PICs206A and206B by one of PFEs204 (Act303). In one implementation, one of thecontrol PICs206A and206B, such ascontrol PIC206A, is designated as a “master” control PIC. Themaster control PIC206A receives all initial connection requests formSGSN106.

Master control PIC206A may then forward the received request to one of the other “slave” control PICs, such ascontrol PIC206B (Act304). Theslave control PIC206B may then communicate with designated servers incorporate network114 to establish that a mobile user/device is attempting to initiate a connection (Act305). One of ordinary skill in the art will recognize that the slave control PIC may communicate with networks other than a corporate network. The use of a master control PIC and slave control PICs allows the master control PIC to efficiently balance incoming requests among the available slave control PICs.Corporate network114 may include RADIUS (remote authentication dial-in user service) and DHCP (dynamic host configuration protocol) servers. RADIUS and DHCP servers are well known in the art. In general, a RADIUS server implements a client/server protocol through which the mobile end-user is authenticated tocorporate network114. The DHCP protocol dynamically assigns IP addresses to connecting mobile devices. Address assignment mechanisms other than DHCP may also be used.

Whenslave control PIC206B finishes authentication and address assignment with thecorporate network114, it transfers the session setup information to one ofdata PICs206C and206D (Acts306 and307). The data PIC then validates the setup request and determines whether adequate resources are available for the request (Acts308 and309). If adequate resources are available, the data PIC accepts the setup request and informs the slave control PIC that it has accepted the setup request (Act310). The slave control PIC may respond to the SGSN from which the request came informing it of the successful request (Act311). If adequate resources are not available, the data PIC informs the slave control PIC of the lack of resources (Act312). The slave control PIC may respond to the SGSN from which the request came informing it of the lack of resources (Act313).

Assuming a successful request, the data PIC (i.e.,PIC206C or206D) handles packet forwarding during the communication session between the end-user101 and corporate network114 (Act313). More particularly, the selected data PIC may receive data frommedia cards206E and206F, reformat header information for the data (e.g., encapsulation/decapsulation), as appropriate, and transmit the data to an output one of themedia cards206E and206F.

Although end-users101 have been described as communicating with acorporate network114, in other implementations, end-users101 may communicate with other computing devices or networks.

FIG. 4 is a diagram illustrating a portion ofnetwork100 relating to the call setup procedure illustrated inFIG. 3. The call session established withcorporate network114 is illustrated asGTP tunnel401.Data PIC206C or206D onGGSN107 forwards packets betweenSGSN106 andcorporate network114. ADHCP server402 and RADIUS server403 are also shown incorporate network114.

InGGSN107, as described above, because the forwarding plane is implemented by data PICs that are separate from the control PICs, heavy forwarding activity will have minimal impact on call setup. If additional control or data PICs are required byGGSN107, network administrators can simply add them to FPCs205.Routing engine202 may maintain a table that describes the state and the type of each of PICs206. Accordingly, when a PIC is added or removed,routing engine202 may update its internal table to reflect the change.Routing engine202 may also forward the PIC change information to the control PICs.

Although asingle SGSN106 is shown inFIG. 1, in actual operation,GGSN107 may communicate with multiple SGSNs innetwork100.

CONCLUSION

A GGSN is described herein that includes components of a high-speed router that are adapted to establish communication sessions under GTP. The GGSN includes modular cards that separately implement control and data planes of GTP. The separate data and control cards provide for improved system reliability and improved flexibility in managing bandwidth.

Although the GGSN described above was primarily described as implementing the GTP protocol, other protocols could be similarly implemented.

The foregoing description of preferred embodiments of the invention provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention.

Moreover, while a series of acts has been presented with respect toFIG. 3, the order of the acts may be different in other implementations consistent with principles of the invention. In particular, non-dependent acts may be implemented in parallel. Additionally, lines with arrows are used in the figures to generally illustrate the flow of data. In practice, embodiments consistent with the principles of the invention may send data on these lines in both directions.

No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one” or similar language is used.

The scope of the invention is defined by the claims and their equivalents.

Claims (20)

1. A device comprising:

a first type of interface card to receive a request for a communication session;

a second type of interface card, different from the first type of interface card, to:

receive information, associated with the communication session, from the first type of interface card, and

handle data transfer related to the communication session based on the information;

a first element that includes a plurality of physical slots for receiving the first type of interface card and the second type of interface card,

the first type of interface card and the second type of interface card being independently insertable into any of the plurality of physical slots; and

a second element, different than the first element, to:

create a routing table based on network topology information,

create a forwarding table based on the routing table, and

forward the forwarding table to the first element.

2. The device ofclaim 1, where the device includes a gateway General Packet Radio Service support node (GGSN).

3. The device ofclaim 1, where the device includes a network device.

4. The device ofclaim 1, where the first element includes a plurality of flexible port concentrators, and

where the plurality of physical slots are included in the plurality of flexible port concentrators.

5. The device ofclaim 1, where the first type of interface card performs control plane processing in General Packet Radio Service Tunneling Protocol (GTP), and

where the second type of interface card performs data plane processing in GTP.

6. The device ofclaim 1, where the device further includes:

a third type of interface card, different from the first type of interface card and the second type of interface card, where the third type of interface card includes a transport media card that receives and transmits data on a network.

7. The device ofclaim 6, where the transport media card formats data based on one or more of:

a synchronous optical network (SONET) standard,

or

an Ethernet standard.

8. The device ofclaim 6, where the first type of interface card, the second type of interface card, and the third type of interface card are hot-swappable.

9. A method comprising:

receiving, by a first card in a first network device and from a second network device different than the first network device, a request to establish a communication session with a third network device, in a network, different than the first network device and the second network device;

communicating, by a second card in the first network device and based on receiving information associated with the request from the first card, with the third network device to authenticate a user associated with the second network device, the second card being different than the first card;

transmitting, by the second card to a third card in the first network device, session setup information associated with the communication session, the third card being different than the first card and the second card;

determining, by the third card and based receiving the session setup information, whether resources are available for the request;

forwarding, via the third card, data associated with the communication session based on a result of determining whether the resources are available for the request; and

transmitting, by the second card and to the second network device, information indicating whether the resources are available for the request,

where the first card and the second card are independently insertable into any of a plurality of slots in the first network device.

10. The method ofclaim 9, where the second network device includes a serving node.

11. The method ofclaim 9, where the first card and the second card are hot-swappable.

12. The method ofclaim 9, further comprising:

validating, by the third card, the request prior to determining whether the resources are available for the request; and

transmitting, by the third card and to the second card, information indicating whether the third card has accepted the request, based on determining whether the resources are available for the request.

13. The method ofclaim 9, where the first network device includes a gateway GPRS support node (GGSN), and

where the second network device includes a serving General Packet Radio Service (GPRS) support node (SGSN).

14. The method ofclaim 9, further comprising:

performing, by the first card, control plane functions in General Packet Radio Service Tunneling Protocol (GTP) for calls received by the second network device; and

performing, by the second card, data plane functions in GTP for communication sessions associated with the calls.

15. The method ofclaim 9, further comprising:

formatting, by the third card, the data, associated with the communication sessions, based on one or more of:

a synchronous optical network (SONET) standard, or

an Ethernet standard.

16. A system comprising:

a gateway node coupled to at least one serving node via a packet network, the gateway node including a plurality of physical slots to receive:

at least one first interface card to perform control plane functions in General Packet Radio Service Tunneling Protocol (GTP) for wireless calls received by the at least one serving node, and

at least one second interface card, different from the at least one first interface card, to receive information relating to communication sessions, associated with the wireless calls, from the at least one first interface card and to perform data plane functions in GTP for the communication sessions,

where the at least one first interface card and the at least one second interface card are independently insertable into any of the plurality of physical slots.

17. The system ofclaim 16, where the serving node includes a serving General Packet Radio Service (GPRS) support node (SGSN), and

where the gateway node includes a gateway GPRS support node (GGSN).

18. The system ofclaim 16, further comprising:

at least one third interface card, different from the at least one first interface card and the at least one second interface card, to receive and transmit data associated with the communication sessions.

19. The system ofclaim 18, where the at least one third interface card is to format the data based on one or more of:

a synchronous optical network (SONET) standard, or

an Ethernet standard.

20. The system ofclaim 18, where the at least one first interface card, the at least one second interface card, and the at least one third interface card are hot-swappable.

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